the spasmodic affections of the alimentary canal become very violent, and are communicated in a considerable degree to other parts of the body, or when a dangerous debility seems to be induced, the irritation is to be immediately obviated by opiates in sufficiently large doses, but in small bulk, and given either by the mouth or by glyster.

1464. Though the patient be in this manner relieved, it frequently happens, that when the operation of the opium is over, the disease shews a tendency to return; and, for at least some days after the first attack, the irritability of the intestines, and their disposition to fall into painful spasmodic contractions, seem to continue. In this situation, the repetition of the opiates, for perhaps several days, may come to be necessary; and as the debility commonly induced by the disease favours the disposition to spasmodic affections, it is often useful and necessary, together with the opiates, to employ the tonic powers of the Peruvian bark.

CHAP. XI.

OF DIARRHOEA OR LOOSENESS.

1465. THIS disease consists in evacuations by stcol, more frequent, and of more liquid matter

than usual. This leading and characteristic symp tom is so diversified in its degree, in its causes, and in the variety of matter evacuated, that it is almost impossible to give any general history of

the disease.

1466. It is to be distinguished from dysentery, by not being contagious; by being generally without fever; and by being with the evacuation of the natural excrements, which are, at least for some time, retained in dysentery. The two diseases have been commonly distinguished by the gripings being more violent in the dysentery; and they are commonly less violent and less frequent in diarrhoea but as they frequently do occur in this also, and sometimes to a considerable degree, so they do not afford any proper distinction.

1467. A diarrhoea is to be distinguished from cholera chiefly by the difference of their causes; which, in cholera, is of one peculiar kind; but in diarrhoea is prodigiously diversified, as we shall see presently. It has been common to distinguish cholera by the evacuation downwards being of bilious matter, and by this being always accom. panied with a vomiting of the same kind; but it does not universally apply, as a diarrhoea is sometimes attended with vomiting, and even of bilious matter.

1468. The disease of diarrhoea, thus distinguish

ed, is very greatly diversified; but in all cases, the frequency of stools is to be imputed to a preterna tural increase of the peristaltic motion in the whole, or at least a considerable portion, of the intestinal canal. This increased action is in different degrees, is often convulsive and spasmodic, and at any rate is a motus ab normis: for which reason, in the Methodical Nosology, I have referred it to the order of Spasmi, and accordingly treat of it in this place.

1469. Upon the same ground, as I consider the disease named Lientery to be an increased peristaltic motion over the whole of the intestinal canal, arising from a peculiar irritability, I have considered it as merely a species of diarrhoea. The idea of a laxity of the intestinal canal being the cause either of lientery, or other species of diarrhoea, appears to me to be without foundation, except in the single case of frequent liquid stools from a palsy of the sphincter ani.

1470. The increased action of the peristaltic motion, I consider as always the chief part of the proximate cause of diarrhoea: but the disease is further, and indeed chiefly, diversified by the different causes of this increased action; which we are now to inquire into.

1471. The several causes of the increased ac

VOL. II,

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tion of the intestines may be referred, I think, in the first place, to two general heads.

The first is, of the diseases of certain parts of the body which, either from a consent of the intestines with these parts, or from the relation which the intestines have to the whole system, occasion an increased action in the intestines, without the transference of any stimulant matter from the pri mary diseased part to them.

The second head of the causes of the increased action of the intestines is of the stimuli of various kinds, which are applied directly to the intestines themselves.

1472. That affections of other parts of the system may affect the intestines without the transference or application of any stimulant matter, we, learn from hence, that the passions of the mind do in some persons excite diarrhoea.

1473. That diseases in other parts may in like manner affect the intestines, appears from the dentition of infants frequently exciting diarrhoea. I believe that the gout often affords another instance of the same kind; and probably there are others also, though not well ascertained.

1474. The stimuli (1471) which may be applied to the intestines, are of very various kinds; and are either,

1, Matters introduced by the mouth;

2, Matters poured into the intestines by the several excretories opening into them;

3, Matters poured from certain preternatural openings made into them in certain diseases.

1475. Of those (1474, 1), introduced by the mouth, the first to be mentioned are the aliments commonly taken in. Too great a quantity of these taken in, often prevents their due digestion in the stomach; and by being thus sent in their crude, and probably acrid, state to the intestines, they frequently excite diarrhoea.

The same aliments, though in proper quantity, yet having too great a proportion, as frequently happens, of saline or saccharine matter along with them, prove stimulant to the intestines, and excite diarrhoea.

But our aliments prove especially the causes of diarrhoea, according as they, from their own nature, or from the weakness of the stomach, are disposed to undergo an undue degree of fermentation there, and thereby become stimulant to the intestines. Thus acescent aliments are ready to produce diarrhoea; but whether from their having any directly purgative quality, or only as mixed in an over-proportion with the bile, is not well determined.

1476. Not only the acescent, but also the pu